Cleaning brush with dust removing and collecting means

ABSTRACT

A cleaning brush includes a casing having a dust collecting compartment. An arcuate outer brush is fixed to the casing. An arcuate inner brush is movable with respect to said outer brush. Short bristles are implanted on the outer surface of the inner brush and lean toward the outer brush. Short bristles are also implanted on the inner surface of the outer brush and lean in the same direction as the bristles of the inner brush.

D United States Patent 11 1 1111 3,747,152 Tsuruzawa 1 July 24, 1973 I CLEANING BRUSH WITH DUST REMOVING 966,565 8/1910 Koref 15/38 11x AND COLLECTING MEANS 1,227,412 5/1917 Fendrich 15/22 C 1,487,052 3/1924 Enomoto 15/210 R [7 5] Inventor: Teruya Tsuruzawa, Suita, Japan FOREIGN PATENTS OR APPLICATIONS [73] Asslgnee' Nlppon Seal Osaka Japan 643,295 5/1928 France 15 27 [22] Filed: Feb. 28, 1972 1,934,025 l/l97l Germany 15/48 2,060,377 6/1971 Germany 15/48 PP 129,691 13,383 6/1902 Great Britain 19/108 [30] Foreign Application Priority Data Primary Examiner-Daniel Blum Mar. 4, 1971 Japan 46111503 Attorney-B Wenderoth Jerry Nolton t Sept. 14, 1971 Japan 46/71481 [57] ABSTRACT [52] US. Cl 15/22 C, 15/48, 15/106, i

15/160, 15/221, 19/108 A cleaning brush includes a casing having a dust col- 5 Int. Cl A46, 7/06 A46]J 9/02 A46b 17/06 lecting compartment. An arcuate outer brush is fixed 58 Field 61 Search 15 22 c, 27, 5s, H119 s- An arcuate inner brush is movable with 15/4 104 A, 104 E, 1043 10 1 0 201 respect to said outer brush. Short bristles are implanted 210 R 19/103; 26/31; 209/109 on the outer surface of the inner brush and lean toward the outer brush. Short bristles are also implanted on the [56] References Cited inner surface of the outer brush and lean in the same UNITED STATES PATENTS direction as the bristles of the inner brush.

568,958 l0/l'896 Robertson 15/38 X 10 Claims, 11 Drawing Figures PAIENIEDJUL24 ms 3.747.152

SHEEI 2 OF 4 sum .3 or 4 3'747'152 PATENTED JUL 24 I15 PATENTEDJUL 24 I975 SHEET Q [If 4 CLEANING BRUSH WITH DUST REMOVING AND COLLECTING MEANS This invention relates to a brush for cleaning and more particularly to a brush having leaned bristles for cleaning and means for automatically removing dust or the like taken up by and accumulated among the bristles and also means for collecting the dust or the like so removed from the bristles.

A cleaning brush provided with a brush surface having numerous short bristles closely implanted thereon and inclined or leaned in the same or one direction is known (US. Pat. No. 3,421,171 patented Jan. 14, 1969). Because of its outstanding cleaning effect, this type of cleaning brush has introduced an innovation in the conventional concept of brushes for cleaning. Thus when the brush is moved on an article to be cleaned in the direction of the inclination of the bristles and in sliding contact therewith dust, lint or the like (hereinaf ter referred to simply as dust,) is readily swept off the article and caught up among the bristles, and unless subjected to an external force, the dust is retained among the bristles against dropping. This new type of brush may well be regarded as an innovation from the viewpoint of its surprising cleaning effect in contrast with a conventional brush comprising relatively long and vertical bristles which merely serve to .move dust from one place to another or to brush the dust 'off an article to be cleaned.

In spite of the remarkable cleaning effect, however, the brush of the type described above has a drawback. More specifically, although the brush achieves such an outstanding cleaning effect that the dust once swept and taken up among the bristles will not drop therefrom unless subjected to an external force, this remarkable advantage inevitably results in the necessity that the brush surface itself has to be cleaned frequently because the dust deposited or accumulated among the bristles will deteriorate the brushing action and effect. Further, in order to remove the dust accumulated in the brush surface, it has to be rubbed with considerable pressure by a cloth, tooth brush or the like in the direction of leaning of the bristles. This is not only troublesome but also undesirable since the hands will get soiled.

Therefore it is an object of this invention to provide a brush of the type described above but having no such drawback as explained above.

A more particular object of this invention is to provide a brush of the type described above but having means for automatically removing dust from the brush surface.

Another object of this invention is to providev a brush of the type described above but having means for automatically removing dust from the brush surface and for collecting the dust so removed.

Other objects of this invention will become apparent from the following description.

Briefly, the brush according to this invention comprises at least one pair of a fixed arcuate outer brush member and a correspondingly arcuate inner brush member which is movable toward and away from the outer brush member and in sliding contact therewith, short bristles closely implanted on the outer surface of the inner brush member to form a cleaning brush surface, short bristles closely implanted on the inner surface of the outer brush member to form a dust removing surface, the bristles on the inner brush member being leaned in the direction of the outer brush member, the bristles on the outer brush member being leaned in the same direction as that of the bristles on the inner brush member, a casing for holding the inner and outer brush members, and a dust collecting compartment formed within the casing, the arrangement being such that when the inner brush member is in the first position most away from the outer brush member the brush surface of the inner brush member is exposed and engageable with an article to be cleaned for brushcleaning the article and when the inner brush member moves from the first position toward the outer brush member into the second position the bristles on the inner brush member slide on and in contact with the bristles on the outer brush member and when the inner brush member moves back away from the outer brush member from said second position to the first position the bristles on the outer brush member engage with the bristles on the inner brush member so that the dust retained among the bristles on the inner brush member is combed off by and transferred into the bristles on the outer brush member.

Preferably, a stopper means is provided to stop the movement of the inner brush member at each of the first and second positions.

It is preferable that the bristles have a length of 2 7 mm. and the degree of their inclination is 3 particularly 15 60.

If desired, another pair of such inner and outer brush members may be provided. In this case, it is preferable to connect these two pairs so that they are symmetrical to each other and form a unitary structure wherein the arrangement and construction of inner and outer brush members in the first pair may be identical to the second pair, but the direction of inclination of bristles in the first pair should be opposite to that in the second pair.

As mentioned above the inner brush member is movable toward and away from the outer brush member. Preferably the inner brush member is swingable with respect to the outer brush member while the outer brush member is fixed to the casing.

Further, it is preferable that at the first position (i.e.

the position away from the outer brush member) the end portion of the inner brush member close to the outer brush member is not exposed and covered by the end portion of the outer brush member, while at the second position (i.e. the position most close to the outer brush member) the end portion of the inner brush member away from the outer brush member is exposed out of the outer brush member.

The brush having the above mentioned structure and arrangement according to this invention works as follows. Thus, when the inner brush member is in the first position most away from the outer brush member the outer surface (i.e. cleaning brush surface) hearing the unidirectionally leaned bristles of the inner brush member is exposed and engageable with an article to be cleaned. When the brush, in this first position, is moved in the direction of inclination of the bristles while contacting the exposed brush surface of the inner brush member with an article to be cleaned, the leaned bristles on the brush surface engage the article to perform brushing and the dust on the article is swept off and taken up and retained among the bristles on the cleaning brush surface. The cleaning action and effect bristles on the outer brush member, the dust retained or accumulated in the brush surface of the inner brush member as a result of the preceding cleaning or brushing step remains in the brush surface without being removed by the bristles on the outer brush member.

Then the inner brush member is moved back away from the outer brush member from said second position to the first position. During this movement the bristles on the outer brush member engage with the bristles on the inner brush member so that the dust retained among the bristles on the inner brush member is combed off by and transferred into the bristles (i.e. dust removing surface) on the outer brush member. Thus the cleaning brush surface of the inner brush member is cleaned by the dust removing surface of the outer brush member and is rendered ready for the subsequent brushing operation at the first position.

After conducting the brushing at this first position in the manner as expalined hereinbefore, the inner brush member is again moved toward the direction of the outer brush member into the second position. During this movement the dust taken-up by and in the brush surface of the inner brush member is retained therein for the reason explained before, while the dust already taken up and retained among the bristles (i.e. bristles on the dust removing surface) on the outer brush member is pushed and forced within the dust removing bristles but toward the direction of the movement of the inner brush member by the tips of the advancing leaned bristles on the inner brush member.

With repetition of such operation, the dust on the outer brush member is gradually pushed up and finally out of the outer brush member into the dust collecting compartment. Thus, the cleaning brush surface or the bristles on the inner brush member is kept clean always before brushing for cleaning an article is conducted while the dust taken-up by the bristles on the inner brush member after the brushing is transferred to the bristles on the outer brush member and is ultimately collected out of the outer brush member into the dust collecting compartment. The dust accumulated within the dust collecting compartment may be disposed of by any suitable manner.

The invention will be further explained by referring to the accompanying drawings wherein:

FIG. I is a schematic perspective view, partly broken, of a brush embodying the present invention;

FIG. 2 is a cross-sectional view of the brush shown in FIG. 1;

FIG. 3 is a schematic cross-section taken along the line III III in FIG. 1;

FIG. 4 is a cross-sectional view similar to FIG. 2 but showing another embodiment of this inventIon and taken along the line X Y in FIG. 7, each of the right inner brush member and left inner brush member being in a position between the first and second positions.

FIG. 5 is a view similar to FIG. 4 but showing the state wherein the right inner brush member is in the first position while the left inner brush member is in second position;

FIG. 6 is a view similar to FIG. 4 or 5 but showing the state where the right inner brush member is in the second position while the left inner brush member is in the first position;

FIG. 7 is a vertical-sectional view taken along the line X Y in FIG. 4;

FIG. 8 is a plan view of the brush shown in FIG. 4, as seen from below;

FIG. 9 is a cross-sectional view similar to FIG. 2 but showing still another embodiment of the invention;

FIG. 10 is a perspective view of the embodiment shown in FIG. 9; and

FIG. 11 is a cross-sectional view similar to FIG. 2 but showing still another embodiment of the invention.

Referring first to FIGS. 1, 2 and 3 which show a first embodiment of this invention which has only one pair of cooperating inner and outer brush members, the brush comprises an inner brush member A having an arcuate cross section, an outer brush member B having a corresponding arcuate cross section and a casing C consisting of a first upper section 1, second upper section 2, front end wall 3 and back end wall (not shown). The outer arcuate brush member B is fixed at its upper end to the marginal edge of the casing section 2 by a suitable means 4 such as a hinge or the like. The outer brush member B is further fixed to the front and back end walls. An arcuate guide wall 5 having the same curvature as that of the inner and outer brush members is connected at its one end to the marginal edge of the casing section 1 by a suitable means 6 such as a hinge or the like. The guide wall 5 extends toward and along the major portion of the outer brush member B but is inwardly spaced from the inner surface of the outer brush member and terminates at its free upper end with a space 7 from the inner surface of the casing section 2 as well shown in FIG. 2.

The arcuate inner brush member A is mounted so as to be slidably movable along the outer arcuate surface of the guide wall 5 and toward and away from the outer brush member B. The space between the outer arcuate surface of the guide wall 5 and inner arcuate surface of the outer brush member B serves as a passage for the inner brush member A. Adjacent to the connection with the casing section 1 the guide wall 5 is provided with a stopper 8 which is slightly lower than and engageable with an operating projection 9 projecting outwardly and formed at one end of the inner brush member A. On the outer surface of the inner brush member A there are closely implanted numerous short bristles 10 inclined toward the outer brush member B (i.e. toward the space 7) to form a cleaning brush surface. Similarly on the inner surface of the outer brush member B there are closely implanted numerous short bristles 11 which are similarly inclined in the same direction as that of the bristles 10 on the inner brush member A as well shown in FIG. 2 to form a dust removing surface.

The inner brush member A may be slidably mounted in any suitable manner. Thus, for example, in the embodiment shown in FIGS. 1 3, a small arcuate projection 12 is provided along each of the front marginal end and back marginal end of the inner brush member A. The front projection 12 engages with and is slidably movable within a correspondingly arcuate groove 13 formed along the lower end portion of the inner face of the front end wall 3. Similarly, the back projection (not shown) on the inner brush member A is engaged with the corresponding groove (not shown) formed on the inner wall of the back end wall (not shown).

The dimensional (lengthwise) relation between the inner brush member A and outer brush member B is preferably such that when the inner brush member A is in the first position (i.e. the position most away from the outer brush member B) shown in FIG. 2 the right end marginal portion of the inner brush member A is not exposed out but is covered by the left end marginal portion of the outer brush member B as well shown in FIG. 2.

It is preferable to provide the outer face of the outer brush member B with bristles 14 leaned in one direction or short vertical piles such as a velvet fabric.

The space within the casing constitutes a dust collecting compartment D which communicates through the space 7 with the space between the guide wall 5 and outer brush member B.

In FIG. 2 the innerbrush member A is in the first position wherein it is most away from the outer brush member B and is exposed for engagement with an article to be cleaned (not shown) in order to conduct brushing operation. In operation starting from this first position shown in FIG. 2, the casing C is grasped by the hand and the brush is moved on an article to be cleaned in the direction of the arrow (i.e. in the direction of the inclination of the bristles) to cause the leaned bristles to engage the article for brushing, whereupon dust on the article is swept and taken up among the tips of the bristles 10 to achieve efficient brush-cleaning of the article.

Then the inner brush member A is moved toward the outer brush member B. This movement may be conducted manually or by moving the brush in the opposite direction (i.e. in the direction opposite to the arrow in FIG. 2) while engaging the projection 9 with the article to be cleaned. This movement may be continued until the projection 9 on the inner brush member A engages the lower or free end of the outer brush member B. During this movement the bristles 10 on the inner brush member A will move on and in sliding contact with the bristles 11 on the outer brush member B. Since the direction of inclination of the bristles 10 on the inner brush member A is same as that of the bristles 11 on the outer brushm'ember B, the dust retained or accumulated in the brush surface of the inner brush member A as a result of the preceding cleaning or brushing step remains in the brush surface without being removed by the bristles ll on the outer brush member B.

Then the inner brush member A is moved back away from the outer brush member B, i.e. from the second position to the first position shown in FIG. 2. This movement may be conducted manually or by moving the brush in the direction of the arrow in FIG. 2 while engaging the projection 9 with the article to be cleaned. This. movement may be continued until the projection 9- on the inner brush member A engages the stopper 8. During this movement the bristles 11 on the outer brush member B engage with the bristles 10 on the inner brush member A so that the dust retained among the bristles 10 is combed off by and transferred into the bristles 11 (i.e. dust removing surface) on the outer brush member B. Thusthe rush surface on the inner brush member A is cleaned by the dust removing surface of the outer brush member B and is rendered ready for the subsequent brushing operation at the first position.

After conducting the brushing at this first position in the manner as explained hereinbefore, the inner brush member A is again moved toward the direction of the outer brush member B into the second position. During this movement the dust taken-up by and in the brush surface of the inner brush member A is retained therein for the reason explained before, while the dust already taken up and retained among the bristles 11 (i.e. bristles on the dust removing surface) on the outer brush member B is pushed and forced within the dust removing bristles but upward and toward the direction of the movement of the inner brush member A by the tips of the advancing leaned bristles 10 on the inner brush member A.

With repetition of such operation, the dust on the outer bru'sh member B is gradually pushed up and finally out of the outer brush member B into the dust collecting compartment D through the space 7. Thus, the cleaning brush surface or the bristles 10 on the inner brush member A is kept clean always before brushing for cleaning an article is conducted, while the dust taken-up by the bristles on the inner brush member A after the brushing is transferred to the bristles 1 1 on the outer brush member B and is ultimately collected out of the outer brush member into the dust collecting compartment D. The dust accumulated within the dust collecting compartment D may be disposed of by any suitable manner. For example the casing C may be opened for such purpose. If desired, an opening (not shown) of a suitable shape may be formed on the casing C and an attachment of vacuum cleaner may be fitted in such opening for suction removal of the dust accumulated in the dust collecting compartment D.

The provision of the bristles 14 on the outer surface of the outer brush member B will serve to release the dust from the article to be cleaned in advance to the cleaning action by the inner brush member A.

FIGS. 4 8 show another embodiment of the invention wherein there are symmetrically provided two pairs of inner and outer brush members connected into a unitary structure, one pair constituting the left half while the other pair constituting the right half of the brush. A casing is common to these two pairs. The direction of inclination of the bristles in the first pair is made opposite to that in the second pair. The two inner brush members are connected with each other to form a semi-cylindrical body which is rotatably mounted on the casing to which both outer brush members are fixed. The operative relationship between the inner and outer brush members in each pair is substantially identical to that explained before in respect of the embodiment shown in FIGS. ll 3. Therefore, in order to facilitate understanding and to simplify the explanation the members corresponding to those already explained and shown in FIGS. 1 3 will be designated with the same reference numerals as used in FIGS. 1 3 except that the members in the left pair are designated with primed numerals.

Thus in the embodiment shown in FIGS. 4 8, there is provided an outer semicylindrical body, the lower peripheral position of which is cut off to provide a lower opening 16. Thisouter semicylindrical body constitutes a casing C, the lower portion of which respectively constitute outer brush members B and B. Leaned short bristles 11 and 11 are closely implanted on the inner surface of the outer brush members B and B respectively. Within the outer semicylindrical body and inwardly spaced therefrom is rotatably mounted an inner semicylindrical body constituting the inner brush members A and A. The upper peripheral portion of the inner semicylindrical body is cut off to provide an upper opening 17. Leaned short bristles l and 10' are closely implanted respectively on the outer right half surface and left half surface respectively of the inner semicylindrical body. These bristles are inclined in the same manner as explained before in respect of the embodiment shown in FIGS. 1 3, but it should be noted that the direction of inclination of the bristles in the left half (left inner brush member A) is opposite to that in the right half (right inner brush member A) as well shown in FIGS. 4 6. Indicated with D is a dust collecting compartment into which the dust is collected through the spaces 7 and 7. Indicated with 3,3 are front and back end walls of the casing, and the front and back end plates 19,19 provided at the front and back ends of the inner semicylindrical body are rotatably mounted at 20,20 to the front and back end walls 3,3 respectively. On the top inner wall of the outer semicylindrical body there is provided a stopper 21 which, upon rotation of the inner semicylindrical body, is engageable with the shoulders 22, 22' formed at the side marginal edges of the inner brush members A and A to stop the movement of these members.

The dimensional relationship between the inner brush members A, A and outer brush members B, B is such that when one of the inner brush members A, A is in the position most away from the corresponding outer brush member the bristles on the other inner brush member are partly exposed out of the corresponding outer brush member as shown in FIGS. 5 and 6 so that the so exposed bristles can engage with the article to be cleaned.

Further, it will be noted that the arrangement is such that when one of the inner brush members A, A is in the first position (most away from the corresponding outer brush member) the other inner brush member will take the second position (most close to the corresponding outer brush member B or B).

In operation, when the back of the casing C (or outer semicylindrical body) in the position shown in FIG. 4 is held by the hand and the brush is moved in the direction of the solid arrow with the bristles on the inner brush members A, A in contact with the article (not shown) to be cleaned, the inner semicylindrical body would be moved in the opposite direction (i.e. in the direction of the dotted arrow in FIG. 4) since the tips ofthe bristles 10 on the right inner brush member A engages with the article. This movement is discontinued when the shoulder 22' strikes the stopper 21 whereupon the brush is brought into the position shown in FIG. 5.

When the brush in this state of FIG. 5 is further moved on an article to be cleaned in the direction of the solid arrow (FIG. 5) the bristles 10 on the right inner brush member A exposed out of the right outer brush member B will engage the article for brushing and the dust on the article is swept and taken-up among the bristles 10.

Then the brush is moved in the opposite direction (i.e. in the direction of the dotted arrow in FIG. 5) on and in contact with the article, the inner semicylindrical body is driven in the opposite direction (i.e. in the direction of the solid arrow in FIG. 5) due to the engagement of the partly exposed bristles 10' with the article until the shoulder 22 strikes the stopper 21 whereupon the brush is brought into the position shown in FIG. 6.

When the brush in this state of FIG. 6 is further moved on the article in the same direction (i.e. in the direction of the dotted arrow in FIG. 6) the bristles 10 on the left inner brush member A now exposed out of the left outer brush member B will engage the article for brushing and the dust on the article is swept and taken-up among the bristles 10.

Then the brush is moved in the opposite direction (i.e. in the direction of the solid arrow in FIG. 6) on and in contact with the article, the inner semicylindrical body is driven in the opposite direction (i.e. in the direction of the dotted arrow in FIG. 6) due to engagement of the partly exposed bristles 10 with the article until the shoulder 22' strikes the stopper 21 whereupon the brush is brought into the position shown in FIG. 5.

Then the brush is again moved from the position of FIG. 5 to the position of FIG. 6 and this operation may be repeated, with the cleaning or brushing operation at each of the positions of FIGS. 5 and 6 as explained above. The cooperative working relationship between the inner brush member and the corresponding outer brush member in each of the right pair and left pair is identical to each other and to that explained before in respect of the embodiment shown in FIGS. 1 3. Thus, during the movement of the inner brush member A or A into the second position most close to the corresponding outer brush member B or B respectively the dust taken-up by and retained by the inner brush member in the preceding brushing operation is retained therein, but during the movement of the inner brush member away from the corresponding outer brush member into the first position the dust retained among the bristles 10, 10 is taken up by and transferred to the bristles l1, 11 due to the combing engagement therebetween. Thus the cleaning brush surface or bristles l0, 10 on the inner brush member A, A is cleaned by the corresponding dust removing surface or bristles 11, ll on the outer brush member B, B and is rendered ready for the subsequent brushing operation at the first position. When, after conducting the brushing at this first position, the inner brush member A, A is moved toward the corresponding outer brush member B, B into the second position, the dust taken-up by the bristles 10, 10' of the inner brush member remains therein but the dust already taken-up and retained among the bristles 11, 11 on the outer brush member B, B is pushed upwardly within the bristles ll, 11 by the advancing bristles l0, 10 on the inner brush member A, A. With repetition of such operation the dust on the outer brush member B, B is gradually pushed up and ultimately out of the outer brush member into the dust collecting compartment D through the space 7, 7. The dust accumulated in the dust collecting compartment D may be disposed of by any suitable manner. For example, the inner semicylindrical body may be adapted so as to be able to be taken out of the outer semicylindrical body. If desired, an opening (not shown) of a suitable shape may be formed in the casing C and an attachment of vacuum cleaner may be fitted to such opening for vacuum cleaning the interior of the dust collecting compartment D.

The embodiment shown in FIGS. 9 and 10 is identical in the construction and function to that shown in FIGS. 4 8 except that the top of the casing C is flattened to form a flat cover plate on which is provided an opening 26 and that the upper portion of each of the end plates 19, 19 provided respectively at the front and back ends of the inner semicylindrical body forming the inner brush members A and A is in the form of a trapezoid with right slanting edge or shoulder 27 and left slanting edge or shoulder 27' which respectively correspond in the function to the shoulders 22, 22 of the embodiment shown in FIGS. 4 8. The arrangement is such that the movement of the inner semicylindrical body (and hence the inner brush members A and A) is stopped due to the engagement of the slanting edge or shoulder 27 or 27' with the inner surface of the flat cover plate 25. The opening 26 is for the disposal of the dust accumulated in the dust collecting compartment D. If desired the top cover plate 25 may be constructed so as to be detachable to facilitate the disposal of the dust.

In another embodiment shown in FIG. 11, the construction of the inner semicylindrical body with a pair of inner brush members A, A is identical to that of the embodiment shown in FIGS. 4 8. Properly spaced from the inner semicylindrical body and at both sides thereof there are provided a pair of right outer brush member B and left outer brush member B which are adapted to cooperate with the corresponding inner brush members A and A respectively. The lower ends of the outer brush members B and B are connected respectively with bottom brush members E and E extending outwardly. On outer surface of the bottom brush members E and E are closely implanted short bristles 29 and 29' leaned or inclined toward the respective inner brush members A and A as well shown in FIG. 11. The marginal end portion of these bottom brush members E and E are clamped by a casing C through its peripheral bottom frame 30 to form a unitary structure. The inner semicylindrical body is rotatably mounted on and within the casing C in the same manner as in the embodiment shown in FIGS. 4 8. On each end wall of the casing C and at its central portion there is provided a stopper 32 projected inwardly so that the shoulder 22 or 22 is engageable therewith to stop the movement of the inner semicylindrical body bearing the inner brush members A and A. Indicated with the numeral 33 is an opening for the disposal of the dust accumulated in the dust collecting compartment D. The operation, working and effect of this embodiment are again identical to those of the embodiments explained hereinbefore, except that the bristles 29 and 29 on the bottom brush members E and E would assist the brushing action.

What I claim is:

l. A cleaning brush which comprises at least one pair of a fixed arcuate outer brush member and a correspondingly arcuate inner brush member which is movable toward and away from the outer brush member and in sliding contact therewith, short bristles closely implanted on the outer surface of the inner brush member to form a cleaning brush surface, short bristles closely implanted on the inner surface of the outer brushmember to form a dust removing surface, the bristles on the inner brush member being leaned inthe direction of the outer brush member, the bristles on the outer brush member being leaned in the same direction as that of the bristles on the inner brush member, a casing for holding the inner and outer brush members, and a dust collecting compartment formed within the easing, the arrangement being such that when the inner brush member is in a first positioned furthest away from the outer brush member the cleaning brush surface of the inner brush member is exposed and engageable with an article to be cleaned for brush-cleaning and when the inner brush member moves from the first position toward the outer brush member into a second position the bristles on the inner brush member slide on and in contact with the bristles on the outer brush member and when the inner brush member moves back away from the outer brush member from said second position to the first position the bristles on the outer brush member engage with the bristles on the inner brush member so that the dust retained among the bristles on the inner brush member is combed off and by and transferred into the bristles on the outer brush member.

2. A cleaning brush as claimed in claim 1, wherein there are provided two pairs each comprising the fixed outer brush member and movable inner brush member so that these pairs are symmetrical to each other and form a unitary structure, wherein the arrangement and construction of inner and outer brush members in the first pair are identical to those in the second pair, but the direction of inclination of the bristles in the first pair is opposite to that in the second pair.

3. A cleaning brush according to claim 2, wherein said two arcuate inner brush members are connected together in side-by-side relation to form an inner semicylindrical body, while the outer brush members are connected respectively to the lower ends of the casing surrounding the inner semicylindrical body.

4. A cleaning brush according to claim 1, wherein there is provided a stopper means to stop the movement of the inner brush member at each of said first and second positions.

5. A cleaning brush according to claim 1, wherein the casing has a front end wall and back end wall, each provided along its inner lower surface with an arcuate guide groove within which a corresponding arcuate projection provided at the end of the inner brush member is engageable for sliding movement.

6. A cleaning brush according to claim 5 wherein an arcuate guide wall having the same curvature as that of the inner and outer brush members is connected at its end with the casing to extend along and inwardly apart from the outer brush member, and the inner brush member is movable in the space between the outer brush member and the arcuate guide wall.

7. A cleaning brush according to claim 6 wherein there is provided on the inner brush member a projection which is engageable with a stopper provided on the guide wall and with the lower free end of the outer brush member to stop the movement of the inner brush member.

8. A cleaning brush according to claim 3 wherein an end'plate is provided at one end of the inner semicylindrical body, said end plate being partly cut-off to provide a shoulder which is engageable with a stopper means formed on the casing.

9. A cleaning brush according to claim 3 wherein the outer brush members are connected respectively to the lower ends of the casing through bottom brush members, on the outer surface of which are closely implanted short bristles inclined toward the inner semicylindrical body.

10. A cleaning brush according to claim 8 wherein 

1. A cleaning brush which comprises at least one pair of a fixed arcuate outer brush member and a correspondingly arcuate inner brush member which is movable toward and away from the outer brush member and in sliding contact therewith, short bristles closely implanted on the outer surface of the inner brush member to form a cleaning brush surface, short bristles closely implanted on the inner surface of the outer brush member to form a dust removing surface, the bristles on the inner brush member being leaned in the direction of the outer brush member, the bristles on the outer brush member being leaned in the same direction as that of the bristles on the inner brush member, a casing for holding the inner and outer brush members, and a dust collecting compartment formed within the casing, the arrangement being such that when the inner brush member is in a first positioned furthest away from the outer brush member the cleaning brush surface of the inner brush member is exposed and engageable with an article to be cleaned for brush-cleaning and when the inner brush member moves from the first position toward the outer brush member into a second position the bristles on the inner brush member slide on and in contact with the bristles on the outer brush member and when the inner brush member moves back away from the outer brush member from said second position to the first position the bristles on the outer brush member engage with the bristles on the inner brush member so that the dust retained among the bristles on the inner brush member is combed off and by and transferred into the bristles on the outer brush member.
 2. A cleaning brush as claimed in claim 1, wherein there are provided two pairs each comprising the fixed outer brush member and movable inner brush member so that these pairs are symmetrical to each other and form a unitary structure, wherein the arrangement and construction of inner and outer brush members in the first pair are identical to those in the second pair, but the direction of inclination of the bristles in the first pair is opposite to that in the second pair.
 3. A cleaning brush according to claim 2, wherein said two arcuate inner brush members are connected together in side-by-side relation to form an inner semicylindrical body, while the outer brush members are connected respectively to the lower ends of the casing surrounding the inner semicylindrical body.
 4. A cleaning brush according to claim 1, wherein there is provided a stopper means to stop the movement of the inner brush member at each of said first and second positions.
 5. A cleaning brush according to claim 1, wherein the casing has a front end wall and back end wall, each provided along its inner lower surface with an arcuate guide groove within which a corresponding arcuate projection provided at the end of the inner brush member is engageable for sliding movement.
 6. A cleaning brush according to claim 5 wherein an arcuate guide wall having the same curvature as that of the inner and outer brush members is connected at its end with the casing to extend along and inwardly apart from the outer brush member, and the inner brush member is movable in the space between the outer brush member and the arcuate guide wall.
 7. A cleaning brush according to claim 6 wherein there is provided on the inner brush member a projection which is engageable with a stopper provided on the guide wall and with the lower free end of the outer brush member to stop the movement of the inner brush member.
 8. A cleaning brush according to claim 3 wherein an end plate is provided at one end of the inner semicylindrical body, said end plate being partly cut-off to provide a shoulder which is engageable with a stopper means formed on the casing.
 9. A cleaning brush according to claim 3 wherein the outer brush members are connected respectively to the lower ends of the casing through bottom brush members, on the outer Surface of which are closely implanted short bristles inclined toward the inner semicylindrical body.
 10. A cleaning brush according to claim 8 wherein the end plate of the inner semicylindrical body is rotatably connected to the corresponding end wall of the casing. 